Cyclists, pedestrians and skateboarders abound during the festival, which encourages Angelenos to explore and enjoy the city without their cars.

Traffic was heavy in and around downtown Los Angeles on Sunday, but not for the reasons one might expect in a city known for freeways, angry drivers and bumper-to-bumper frustration.

Organizers estimate about 100,000 bicyclists, pedestrians and skateboarders flooded much of Spring, Figueroa, West 7th and East 4th streets and beyond as part of the city's fifth CicLAvia festival, which bills itself as the city's biggest block party. More than nine miles of city streets stretching from Boyle Heights to MacArthur Park and from Chinatown to Exposition Park were closed to motor vehicles for five hours.

"This is a great way for all of us to get together as a city," City Councilman Jose Huizar said at a news conference before Sunday's event. The idea behind CicLAvia is to encourage people to get out of their cars and explore the city in other ways.

"When you have an event that draws more than 100,000 people and you just see a sea of bicycles, a sea of people walking, a sea of pedestrians and families getting together," Huizar said, "that speaks more to promoting bicycle use in the city of L.A. than any piece of legislation we could pass."

The festival was inspired by Bogota, Colombia's weekly ciclovía (Spanish for "bike path") events, which began more than three decades ago and have been adopted by several other cities in Latin America and the United States.

Los Angeles held its first CicLAvia in October 2010, blocking off more than seven miles of streets from Boyle Heights to East Hollywood. There have been four others since, including Sunday's, and the event remains hugely popular.

Before that first L.A. event, it perhaps seemed optimistic to imagine 100,000 people coming out to participate. But now drawing such a crowd is par for the course, and CicLAvia is working to expand into other parts of the city and other cities in L.A. County. Already, the route has been inching farther and farther into South and East Los Angeles.

"People love CicLAvia because it is incredibly fun, and there is a sense of camaraderie and community that is rare for a city as large and diverse as ours," CicLAvia co-founder Aaron Paley said in a statement.

At the news conference, Councilman and mayoral candidate Eric Garcetti said he would like to see CicLAvia become a monthly event.

CicLAvia participant Leonard Kausing, 33, said that idea suits him "as long as it benefits both" local businesses and residents.

For 20-year-old Jazmine Kwong, a neuroscience student at USC, riding her bicycle Sunday was a chance to get a new perspective on the city.

Sunday's event did indeed feel like a block party, albeit a bit more formal and with lots of police around. Music blasted from boomboxes, and DJs played records. There were dozens of food trucks and stands with information about bicycles, health and exercise.

The Mathieu family from Montecito Heights said they were able to discover things in L.A. on Sunday that they had never stopped to appreciate before, such as the 4th Street Bridge that crosses over the L.A. River.

Ruth Mathieu, 33, said they decided to come with their 3-year-old, AmordemiVida — who was getting towed by father Jacques in a small bike carriage — because it was a free event and a good excuse to ride their bicycles.

"We just get to see things we never knew were there," she said. "We're always driving so fast."